The polyether ionophores have been shown to be very effective biological cation (Ca ions K ion, etc.) and amine (norepinephrine) transporters. These substances, represented by X537A (lasalocid), A23187, monensin, etc., appear to be nature's equivalents of crown ethers, and through their complexation of cations or amines, the inonophores from lipid soluble complexes of these polar species that will be passed through the cell membrane. These ionophores are used as antibiotics, and very recently, they have been shown to have dramatic cardiotonic effects. It is possible that these, or related synthetic ionophores, will be useful therapeutic agents for angina and arrhythmia. It is the objective of the proposed work to develop efficient synthesis for these ionophoric polyethers and to test the activity of synthetic materials prepared. The template to be used for testing the synthetic strategy and methodology will be X537A, the total synthesis of which will be pursued by a convergent approach using a building block design for the furan-pyran portion. It is the purpose of this work to make the cyclic ethers from sugars and join them through use of the stereoselective enolate Claisen rearrangement.